I found this on a Smallville website and thought it might be helpful to those who question whether or not Clark can fly yet.
Moderators- You can close the thread if you want I simply did not look if there was a thread on whether or not Clark can fly.
The power that made Clark Kent, or rather, Superman famous, flight allows him to fly from one end of the planet to another. We believe that it is actually latent effect of the bio-electric aura (For more information, please refer to the Invulnerability section) surrounding him. We concluded that not only does the bio-electric aura protects him from harm, it also allow him to defy gravity.
This power was first demonstrated briefly in "Metamorphosis" (Season 1, Episode 2), where Clark was floating on top of his bed and later in "Rosetta" (Season 2, Episode 17), where Clark actually floated, rather than fly, from his bedroom to a highway. Clark has mentioned that he told Lex, who found him and drove him, that he sleepwalked, although he "has no idea how much walking is involved". If this is true, then it should not come as a surprise that Kal-El is able to fly in "Crusade" (Season 4, Episode 1).
For the sake of clarity, from here on, we will refer Kal-El as the emotionless and robotic part of Clark, while Clark as the normal self. The reason why Kal-El is able to fly is probably because he has a higher aptitude in controlling the bio-electric aura, which he used it to cancel out the gravitational force acting on him. It was probably due to this manipulation of bio-electric aura that allows him to "push" against the air around him, allowing him to maneuver in the air, hence, giving the impression that he is able to fly around.
Clark, on the other hand, remains earth-bound is probably because of his inexperience at controlling his bio-electric aura. Also, it was mentioned in the show that he has a fear for flying. This could possibly contribute to his inability to fly, because he is subconsciously or unconsciously suppressing his ability to manipulate the bio-electric aura and fly.
Umm...I'm pretty sure that's wrong buddy. Kal-El's flight comes from being psionic. He can't really fly, it's just that he's a low level telekinetic. Strong enough to make himself move (fly) and anything else close (what he touches).
No, b/c then how could he fly in space??
The Answer is simple, and really quite simple (everyone should know this, it's quite clear due to all the evidence they're given):
Clark CAN fly, he just doesn't know HOW to yet. Just as when he found out he COULD use his xray vision or heat vision, he had to find out HOW to use it, but it was there before he found out how to control it.
Plus, he has shown a certain degree to his "flying". Everytime someone falls from somewhere high, and he jumps after them, he somehow magically defies the rules of gravity and reaches the ground before them? The is physically and scientifically impossible UNLESS he has some control over his being in the air.
As Lionel said "The Details!!" - come on people, the answers are right infront of you.